Two armed ratchet wrench

ABSTRACT

THE WRENCH COMPRISES TWO ARMS PIVOTALLY CONNECTED AS THE ARMS OF SHEARS. THE FIRST ARM IS INTEGRAL WITH A CROWN GEAR WHICH ENGAGES PLANET PINIONS MOUNTED FOR FREE ROTATION ON A PLANET CARRIER WHICH ROTATES ABOUT THE AXIS OF THE CROWN GEAR, THE PLANET PINIONS ENGAGE A CENTRAL SUN GEAR WHICH ROTATES ABOUT SAID AXIS AND WHICH IS SOLID WITH THE TORQUE HEAD OF THE WRENCH AND RATCHET MEANS INTEGRAL WITH THE SECOND ARM ENABLE TO LOCK THE PLANET CARRIER IN ROTATION WITH RESPECT TO SAID SECOND ARM FOR THE ACTUATING OF SAID TORQUE HED DURING THE MOVEMENT OF SAID ARMS, TOWARDS EACH OTHER.

United States Patent Inventor Xavier Marie Joseph Antoine Peyre Brest, France Appl. No. 764,441

Filed Oct. 2, 1968 Patented June 28, 1971 Priority Oct. 2, 1967, Sept. 26, 1968 France 122930 and 167756 TWO ARMED RATCHET WRENCH 57.39, 58.1, 61; 74/142, 792, (inquired) mu l l'il l ii ll niiim "I Primary Examiner-James L. Jones, Jr. Attorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: The wrench comprises two arms pivotally connected as the arms of shears. The first arm is integral with a crown gear which engages planet pinions mounted for free rotation on a planet carrier which rotates about the axis of the crown gear, the planet pinions engage a central sun gear which rotates about said axis and which is solid with the torque head of the wrench and ratchet means integral with the second arm enable to lock the planet carrier in rotation with respect to said second arm for the actuating of said torque head during the movement of said arms, towards each other.

TWO ARMED RATCIIET WRENCH The present invention relates essentially to an improved wrench with a pair of pivotally connected arms.

In the prior state is known a wrench comprising two arms pivotally connected like the arms of shears, one arm of which is integral with at least one gear which operatively controls the rotary drive of the wrench head which consists of a torque transmitting pivot, said pivot being integral with a further gear means, whereas pawls, or like ratchet members are provided for locking the rotary motion of at least one of said gears in a given direction during at least some operating steps, of use of the spanner.

The wrench according to the present invention is of the general type above-mentioned. It is characterized in that the first one of said arms is integral with a crown gear engaged in rotary and meshing relationship by at least one spider gear or planet pinion mounted for free rotation on at least one planet or spider gear carrier, which revolves about the axis of said crown gear and in that said gear integral with said pivot and forming a central sun gear, rotates about the axis of said crown gear while meshing with said planet gear or gears, whereas at least first ratchet means integral with the second ann, enables to lock in at least one direction of rotation the planet gear carrier with respect to said second arm.

Desirably at least second ratchet means are additionally provided integral with the second arm and adapted to lock the pinion of the spanner head in the same direction of rotation as said first ratchet means of the planet gear carrier.

In this manner is provided according to the invention a spanner enabling, upon operating both lever-forming arms for moving them towards each other, to rotate a torque transmitting pivot while introducing a reduction ratio into the rotary controlling motion.

The operation of this spanner is particularly well adapted to working steps wherein it is necessary to apply a torque to a member and wherein the operator is in a state of weightlessness. Moreover, in view of said second pawl, the spanner may be used as a simple spanner or ratchet wrench.

According to an improved feature of the present invention, the spanner head, which consists of said torque transmitting pivot, is formed of a hollow bush or sleeve the inner cross section of which enables the coupling for rotation with interchangeable working members. In particular, this arrangement enables to fit into this hollow, for example polygonal or splined head, any kind of tools such in particular as pipe cutters, spanners of various diameters, nuts, braces, tie rods, stud bolts, etc.

The invention will be better understood by means of the following descriptive specification of a form of embodiment given by way of example only and illustrated in the accompanying drawings wherein:

FIG. I is an exploded perspective view showing the various main elements or components of a spanner made according to the invention;

FIG. 2 is a top view of the spanner shown in FIG. 1, in assembled condition;

3 is a view in section taken right beneath the cover of the head as shown in FIG. 2.

Referring to the embodiment shown in the drawings, the spanner essentially comprises a pair of operating arms 102, 106 which are pivotally connected like the arms of shears and which enable through being actuated, as it will appear hereinafter, to rotate the head 110 of the spanner which head is shaped as a pivot and projects on either side laterally from the opposite sides 20, 21 which close the casing wherein the mechanism is enclosed.

The sidewall of this casing consists in part of a skirt 22 which is integral with the top 20, which in turn is integral with the operating arm 102. The arm 102, the top and the skirt 22 may for instance be made in one piece of metal. The square projecting end 23 of the pivot 110 extends out of the top 20 through an opening 24. A symmetrical opening 25 is provided in the cover 21 for allowing the end 26 of the spanner head 110 to extend outwards therethrough.

The spanner mechanism essentially comprises an internally toothed crown gear 27 integral with the arm 106, made for example in one piece of metal.

The crown gear 27 meshes with four planet pinions which are mounted on pivots 28 on two planet carrier rings 112 and 29, respectively. The pivots 28 are for example suitably riveted within the rings 112 and 29 and the pinions 105 are freely rotatable on the pivots 28.

The spider gears 105 mesh on the other hand with a pinion 30 formed on the pivot of the spanner head, the pivot 110 rotating while being guided within the orifices 24, 25 of the casing.

Therefore, in this mechanism, the pinion 30 has the function of a central sun gear about which the planet gears 105 which mesh therewith, are rotating together with the rings 112 and 29 which revolve simultaneously, the planet gears 105 rolling on the crown gear 27 the axes of which substantially coincides with that of pinion 110.

To enable the operation of the spanner, it is necessary that at least one of the planet carrier rings may be locked in at least one direction of rotation. To this end, the ring 112 is formed for example with teeth 31 which may be engaged for instance by two pawls 32, 33 which are urged by springs 34, 35 into engagement with the inclined teeth of the ring 112. The pawls 32, 33 are mounted for rotation about pivots 36, 37 below the cover 20 wherein said pivots are for example riveted.

There is desirably provided a shoulder 38 in the crown gear 27 for housing and providing the necessary clearance for the pawls 32,33 underneath the cover 20.

The second pawls 39, 40, pivotally connected to pivots 41, 42 beneath the cover 20 of the casing, cooperate with the pinion 30 or better with inclined teeth 43 mounted in the extension of the pinion 30 on the pivot 110. The orientation of the pawls 39, 40 and 32, 33 is the same, as well as the orientation of the teeth 31, 43, so that the first pawls 32, 33 and the second pawls 39, 40 achieve the locking against rotation in the same direction with respect to the cover 20, of the ring 112 and the pivot 110, respectively. Springs 44, 45 urge the pawls 39, 40 against the teeth 43.

Finally the assembly is kept together for example by means of lateral connecting strips, 46 set on the wall 22.

The operation of the device is the following.

it will be assumed to facilitate the explanation that the arm 102 (called the second arm) remains immovable, and that the arm 106 is moved theretowards in the direction of the arrow M (FIG. 3) to rotate same by an angle 6.

During this step, called driving step, the crown gear 27 is driven to rotate by an angle 0.

The ring 112, locked by the pawls 32, 33 mounted on the cover 20 integral with the stationary arm 112 cannot revolve in this (counterclockwise) direction. Under these conditions, the rings 112, 29 remain stationary and spider gears 105 rotate while rolling on the crown gear 27 which moves past them.

The pinions 105 rotate by an angle in in the same direction as the angle 0 (that is in the counterclockwise direction).

At the same time the pinions 105, which mesh with the pinion 30, rotate the latter by an angle 1 in the reverse (or clockwise) direction.

It is readily seen that there is the following correlation between the angle 0 and the angle 1 wherein D and D are the pitch diameters of the crown gear 27 and pinion 30, respectively.

In FIG. 3, it should be noted that during this rotation of the spanner head 110, the pawls 39, 40 are drawn aside thereby allowing this rotation.

It is also seen that during this driving step, the angle of rotation of the spanner head is greater than the angle of rotation corresponding to the drawing near of both spanner arms 102, 106.

The driving step is followed by a dead idle period during which the arm 106 is merely moved backwards in the direction of the arrow R (H6. 3). During this operation, while always assuming the arm 102 to be stationary, the ring 112 being no longer locked by the pawls 32, 33 in this direction, the planet-carrier ring ll2 rotates in the clockwise direction together with the planet gears which simultaneously roll freely on the pinion 30 and the crown gear 27.

It should be noted that if both spanner arms 102, 106 are maintained at the same level, the spanner may be used like a conventional ratchet wrench, the pawls 29, 40 rigidly connecting the head 110 to the arms 102 at each rotation in the clockwise direction of the spanner.

lt is obvious that in practice, when using the spanner, both arms 102, 106 are effectively moved towards each other like the arms of shears; however, it is clear that the operation of the spanner as described is not altered.

If it is desired to use the spanner for obtaining a torque in the opposite direction with respect to that described (torque with angle d in the clockwise direction), it suffices to invert the spanner over upside down.

The use, as a spanner head, of a hollow sleeve 110 with a polygonal or toothed cross section is very advantageous. ln effect, this enables the spanner to receive multiple interchangeable working members, such as for example pipe cutters, wrenches, reducing heads of various diameters, stud bolts, etc... For this purpose, the outer cross-sectional contour of the head may be square as shown or any polygonal, circular or like shape. The inner cross section may at the same time be cogged or of any polygonal and in particular hexagonal shape, or toothed, etc...

lclaim:

l. A two armed ratchet wrench comprising a first and a second arm pivotally connected about an imaginary axis, a crown gear integral with said first arm, a torque transmitting pivot forming the head of the wrench, a central gear solid with said pivot, said crown gear, pivot and central gear rotating about said imaginary axis, at least an intermediate gear meshing with said crown and said central gears, first ratchet means mounted on said second arm for controlling the rotary motion of said pivot in at least one direction during the actuation of said arms, and a casing in which are located said gear and ratchet means, wherein said intermediate gear is a planet gear mounted for free rotation on at least one planet-carrier ring which revolves about said axis, and said ratchet means engage said planet-carrier ring; second ratchet means mounted on said second arm engage said central gear for locking the same in the same direction of rotation as said first ratchet means of the planet carrier.

2. A wrench according to claim 1, wherein said casing is closed by two opposite covers which are provided with central orifices for the passage of both ends of said torque transmitting pivot and its centering within said casing.

3. A wrench according to claim 2, wherein one portion of said casing is made in one piece with said second arm.

4. A wrench according to claim 1, wherein said pivot and central gear consist of one single piece forming a hollow sleeve the inner cross section of which enables the coupling for rotation with interchangeable working members.

5. A wrench according to claim 3, comprising two planetcarrier rings between which are mounted the planet gears, the ring adjacent to that cover of said casing which is integral with said second arm, comprising teeth for its locking by said first ratchet means.

6. A wrench according to claim 4, wherein said hollow sleeve, forming the torsion pivot of the wrench, comprises teeth for its locking by said second ratchet means. 

